Risk factors for incidence and severity of white spot lesions during treatment with fixed orthodontic appliances

Abstract

Introduction: The development of incipient caries, or white spot lesions (WSLs), is a significant clinical problem in orthodontics. The purpose of this study was to retrospectively determine the incidence and severity of WSLs by examining pretreatment and posttreatment digital photographs.

Methods: A total of 332 consecutive finished patients from a university graduate orthodontic clinic were evaluated. Initial and final digital images were compared to assess WSLs. The facial surfaces of the anterior 8 maxillary teeth were analyzed. The percentage area of WSL per total facial tooth surface was calculated to control for magnification differences. Reliability of the method was assessed by comparison with direct clinical examination data. Patient and operator factors, and treatment complexity and outcomes were evaluated as predictors of WSL incidence and severity.

Results: Agreement between direct clinical examination and digital photo data was excellent, with an intraclass correlation coefficient 0.88 and a 0.3% average difference between methods. The incidence of at least 1 WSL on the labial surface of the anterior 8 maxillary teeth was 36%. The order of incidence was lateral incisor (34%), canine (31%), premolar (28%), and central incisor (17%).

Conclusions: Risk factors for the development of incipient caries during orthodontic treatment were young age (preadolescent) at the start of treatment, number of poor hygiene citations during treatment, unfavorable clinical outcome score, white ethnic group, and inadequate oral hygiene at the initial pretreatment examination. The use of computer software to evaluate digital photos retrospectively is a valid method for assessing the incidence and severity of WSLs on the maxillary anterior incisors, canines, and premolars.